The invention relates to a shock absorber for motor vehicles, with tubes that can be pushed into one another. More specifically, to such a shock absorber for vehicle bumpers where the inside tube has an area whose outside contour is larger than the original inside contour of an adjacent area of the outside tube.
This design has the advantage that the deforming force remains approximately constant over the entire deformation path and the energy absorber thus can be deformed over its entire deformation length with the maximum force allowable for the entire structure.
Usual shock absorbers, today, are mostly provided with a flange and are either inserted from outside the vehicle into a component provided for it and screwed in, or are attached on a side member located inside the vehicle. These designs have the drawbacks that, during assembly of the vehicle, the shock absorber must first be brought into the vehicle body and attached and only then can the bumpers or the deflector be attached to it. A complete preassembly of the deflector or of the bumper together with the attachment and the shock absorbers is not possible with these designs.
In the variants inserted into the car body, the screws for attachment of the shock absorber are no longer accessible, and in shock absorbers located in the interior and attached to side members, it is not possible to insert them in the car body in this way, since the openings through the car body are not made large enough. The reason these openings cannot be dimensioned large enough is that too great a weakening of the vehicle structure would take place as a result.
In designs mounted on members, the attachment to the main axis of inertia of the member is eccentric, loading the member until it bends and making a larger design of the member necessary. In addition, also far more space is used up. Further, the shock absorbers attached to the vehicle members must be fixed on both sides with screws to achieve the necessary stability of the attachment. Thus, more screws must be used for attachment.
From German Offenlegungsshrift 24 60 598, a shock absorber of the above-mentioned type is known that is attached to the vehicle body by a mounting plate provided on the end of the outside tube facing away from the inside tube.
A similar type of attachment of a shock absorber with tubes lying inside one another, of which the outside tube widens in a collision, is also known from U.S. Pat. No. 3,915,486.